Control of image output using image processing control data

ABSTRACT

The present invention makes an image data supplier such as an image shooting apparatus controllable of image processing that is performed in an image output apparatus according to image data for the purpose of improving image quality. 
     In the present invention, control data, which is used to control image processing that is performed in an image output apparatus, is set in correlation with image data. A digital camera  10  performs image analysis of shot image data to set control data, and outputs the control data in correlation with the image data. This allows for the control of the image processing that is performed in the image output apparatus. Since the control data is not previously prepared uniform data but is set based on the analysis of the image data, the image processing can be performed as appropriate for each image.

TECHNICAL FIELD

The present invention relates to a technique to control image processingthat is performed in an image output apparatus and to obtain desirableimage outputs.

BACKGROUND ART

A method that enables an image output apparatus e.g. a printer to outputimage data generated by an image shooting apparatus e.g. a digital stillcamera (DSC) as an image is becoming increasingly widespread. Some ofthe image output apparatuses analyze the image data and automaticallyperform image processing for the purpose of improving image quality.Such image processing may include, for example, an adjustment of colorbalances that are used to represent appropriate skin tones of aportrait.

Such image processing, however, is performed in an image outputapparatus regardless of characteristics of each image shootingapparatus, which results in the image processing unable to achieve asufficient level of image adjustment that reflects the characteristicsof each image shooting apparatus. In some cases, the characteristics ofeach image shooting apparatus as well as intentions of each user mayeven be impaired due to unnecessary corrections.

Such a problem is common to any case where an image output apparatusanalyzes image data and performs image processing on its own. Thissimilarly applies to a case where an image output apparatus that issupplied with image data from a server performs image processing andoutputs an image.

The purpose of the present invention is thus to solve the aforementionedproblem and to make an image data supplier such as an image shootingapparatus controllable of image processing that is performed in an imageoutput apparatus according to image data for the purpose of improvingimage quality.

DISCLOSURE OF THE INVENTION

In order to solve at least a part of the aforementioned problem, thepresent invention sets control data, which is used to control imageprocessing that is performed in an image output apparatus, incorrelation with image data. The control data is set in the image outputcontrol apparatus by: inputting image data to be a subject of setting;performing an image analysis; setting the control data; and thenoutputting the control data in correlation with the image data. Thisallows for the control of the image processing that is performed in theimage output apparatus. Since the control data is not previouslyprepared uniform data but is set based on the analysis of the imagedata, the image processing can be performed as appropriate for eachimage.

The image output control apparatus is an apparatus that supplies theimage data and the control data to the image output apparatus, and maybe configured as a server or a computer, for example, that reads aseparately prepared image file, sets the control data, and then suppliesthe control data to the image output apparatus.

The image output control apparatus may also be configured as an imageshooting apparatus that comprises an image shooting module for shootingimages. The image shooting apparatus may include: a digital stillcamera, a digital video camera, a scanner, and such. The image shootingapparatus may analyze output data from the image shooting module, or mayread and analyze an image file that is temporally stored in the imageshooting apparatus. The image shooting apparatus can advantageously makeuse of its characteristics for the setting of the control data.

The present invention can also provide another advantages based on thedifference of throughputs between the image output apparatus and theimage output control apparatus. First, in case where the image outputcontrol apparatus has a lower throughput than the image outputapparatus, the present invention can prevent the image output controlapparatus with the lower throughput from being subjected to an excessiveprocessing load. This is because it is not the image output controlapparatus that completes the image processing in the present invention.On the other hand, since it is the image output control apparatus thatsets the control data, the image output control apparatus can obtain animage output that well reflects the characteristics of the image outputcontrol apparatus.

On the other hand, in case where the image output control apparatus hasa higher throughput, the image output control apparatus can perform animage analysis that is both more advanced and more complex than thatperformed in the image output apparatus. This allows for furtherimprovement in image quality than in case where the image analysis isperformed in the image output apparatus.

Since the present invention makes effective use of the difference ofthroughputs between the image output control apparatus and the imageoutput apparatus, whether or not to perform the image analysis in theimage output control apparatus may be regulated based on the comparisonof throughputs between the apparatuses. The throughput of the imageoutput apparatus may be held in the image output control apparatusbeforehand in correlation with the type of the image output apparatus,or may be inquired by the image output control apparatus into the imageoutput apparatus if the apparatuses are communicative each other. Eachthroughput may be represented with a parameter, e.g. a driving frequencyof a circuit that is used for image processing in each apparatus. Underthe aforementioned regulation, the image analysis may be performed inthe image output control apparatus if the apparatus has a higherthroughput, and may not be performed in the image output controlapparatus if the apparatus has a lower throughput. In the latter case,the image output control apparatus may set the control data that causesthe image output apparatus to perform the image analysis. In thismanner, the image output apparatus may be able to determine easilywhether or not need to perform the image analysis.

Details of the image analysis and the image processing in the presentinvention can be set by various parameters including: contrast,brightness, color balance, white balance, chromaticness, adjustment insharpness, memory color, and etc.

In the present invention, the image output control apparatus may set thecontrol data based on defaults that are prepared beforehand, or may beable to reflect preferences of each user. For example, the image outputcontrol apparatus may store adjustment data that is used to adjusttrends in the setting of control data, so that an analysis module mayreflect the adjustment data to set the control data. The control datacan also reflect preferences of each user if the user sets theadjustment data.

In the present invention, output process of the control data may takevarious aspects. In a first aspect, the control data may be output as animage file that includes the image data and the control data integratedtogether. For example, the image file may take a form of the image datawith the control data embedded in its header. In a second aspect, thecontrol data may be output as a separate file that is associated withthe image file. In a third aspect, the control data may be output to theimage output apparatus via communication.

The present invention is not restricted to the image output controlapparatus and the image shooting apparatus described above, but may alsobe configured in various other aspects. For example, the presentinvention may be a control data setting method that sets control data,which is used to control image processing that is performed in an imageoutput apparatus, in correlation with image data. The present inventionmay also be configured as a computer program that is used to make suchsettings by a computer, and a computer readable recording medium that isrecorded with such a computer program. As for the recording medium,various computer readable recording medium may be used such as aflexible disk, a CD-ROM, a DVD, a magnetic optical disk, an IC card, aROM cartridge, a punch card, a printed material with code such as barcode printed there on, an internal storage (memory such as RAM or ROM)and an external storage of a computer, and etc.

The present invention may also be configured as an image outputapparatus, which is a sub combination to the image output controlapparatus and the image shooting apparatus described above. Such animage output apparatus is configured to: input the image data and thecontrol data; perform the image processing to the image data based onthe control data; and then output an image. The image output apparatusmay also be configured to analyze the image data and perform the imageprocessing as in the prior art, in case where no effective control datawas input or the received control data indicated to perform the imageanalysis.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic that shows the general configuration of an imageoutput system as an embodiment;

FIG. 2 is a schematic that shows the general configuration of a digitalcamera 10;

FIG. 3 is a flowchart of the generation processing of an image file;

FIG. 4 is a flowchart of the image processing;

FIG. 5 is a schematic that shows combinations of modifications in thepresent embodiment.

BEST MODE OF THE INVENTION

Preferred embodiments of the present invention will be described underthe following sections:

-   A. System Configuration-   B. Generation of Image File-   C. Output of Image-   D. Modifications    A. System Configuration

FIG. 1 is a schematic that shows the general configuration of an imageoutput system as an embodiment. The system includes a digital camera 10that functions as an image shooting apparatus; and a personal computerPC and a printer PRT that function as an image output apparatus. Thedigital camera 10 generates an image file when operated by a user. Theimage file is transferred to the image output apparatus via media orcommunication.

The image file contains the image data and its adjunct information asshown. Although the image data is of JPEG format in the presentembodiment, other formats may also be used as well. The adjunctinformation is configured as a header of the image data. In the presentinvention, the header portion is recorded with shooting date, shutterspeed, and other shooting information in the Exif format, which is animage file format for digital still cameras. The header portion is alsorecorded with the control data that is used to control the imageprocessing that is performed in the image output apparatus, as well asoutput regulation information that regulates the number of papers to beoutput. Although the control data and the output regulation informationare recorded in a field that is referred to as MakerNote in the Exifformat in the present embodiment, the recording in this embodiment isnot restricted to this way.

The control data is used to control the details of the image processingthat is performed for the image data in the process of outputting animage. The control data can be classified into two main categories:color space parameters and color correction parameters.

The color space parameters are utilized to transfer color reproductioncharacteristics of the image shooting apparatus to the image outputapparatus so as to realize the accurate color reproduction for eachobject. These parameters include: a gamma correction value responsive tothe characteristics of the image shooting apparatus; and a parameter forspecifying a color space conversion method. The parameter for specifyinga color space conversion method is utilized to specify a color spaceconversion method that is used in the image processing according to thecolor reproduction range available in the image shooting apparatus. Inthe present embodiment, the digital camera 10 uses two types of colorspaces: sRGB and NTSC. Since the color spaces have different colorreproduction ranges, employing the same conversion method for both ofthe color spaces in the image processing may unnecessarily limit thecolor reproduction range of one of the color spaces. The parameter forspecifying a color space conversion method is thus utilized to specify acolor conversion method, so that the image processing can be performedwithout narrowing the color reproduction range expected at the time ofshooting. The parameter for specifying may be set in various formats. Inthe present embodiment, for example, the parameter is set as a parameterthat specifies which color space, i.e. RGB or NTSC, was used at the timeof shooting. The parameter for specifying may also take a form of aconversion matrix that is used in the color space conversion.

The color correction parameters are utilized to transfer the intentionsof the shooter and the characteristics of the digital camera 10 to theoutput apparatus. The parameters include the ones associated with:contrast, brightness, color balance, white balance, chromaticness,sharpness, memory color, and etc. The memory color is a color that isused as a basis of color tone adjustment of the image data. Theaforementioned parameters are merely illustrative, and the control datamay include other parameters as well, or may include only some of theparameters described above.

The personal computer PC reads an image file, analyzes the details ofthe image file, performs the image processing that is specified by thecontrol data, and then prints the image with the printer PRT. Thepersonal computer PC is installed with a software for implementing suchprocessing. As is generally known, the software may be installed intothe personal computer PC via a recording medium such as a CD-ROM or viaa network. Although the combination of the personal computer PC and theprinter PRT constitutes an image output apparatus in the presentembodiment, the computer PC may possibly be eliminated by using aprinter that can implement the image processing all by itself.Alternatively, an image display apparatus such as a display or aprojector may be used to output images instead of the printer.

FIG. 2 is a schematic that shows the general configuration of thedigital camera 10. The digital camera 10 generates image data by meansof an optical circuit 121 that is equipped with CCD for collectingoptical information and an image acquisition circuit 122 for convertingvoltage signals obtained in the optical circuit 121 into image data.

The image data thus obtained is defined in a color space of YCbCr. Thecolor space YCbCr is used here because it is appropriate to the imagecompression in JPEG format. It should be noted, however, that theprocess of obtaining the YCbCr image data from the CCD voltage signalsvaries according to the type of the digital still camera 10.

In general, the digital still camera 10 initially obtains image datathat is defined in a color space of RGB from the voltage signals that isobtained in the CCD. As for the initial color space, one of the twotypes of color spaces, i.e. sRGB or NTSC, is used depending on the typeof the camera. Although either sRGB or NTSC defines colors in acoordinate system of RGB, a coordinate system of NTSC has a broadercolor reproduction range than that of sRGB. The color space sRGB isgenerally defined within a range of 8 bits (0−255), although the spacemay be extended to include negative values or values beyond 256, therebyforming an extended color space (referred to as “an extended sRGB space”herein). The information regarding the color space that was used at thetime of shooting is considered as the information that represents colorreproduction characteristics of the digital still camera 10, and isattached to the image data as a part of the color space parametersdescribed above. It should be noted, however, that the extended sRGBspace and the sRGB space are considered as the same coordinate system inthe present embodiment and are thus represented by the same parameters.The spaces may also be distinguished and represented differently oneanother.

Next, the obtained image of the RGB color space can be applied with 3*3matrix operations and be converted into the YCbCr color space. Thematrix functions to convert the RGB coordinate system into the YCbCrcoordinate system, and is applicable whichever color space, i.e. sRGB orNTSC is used at the time of shooting.

At the time of shooting, a user operates an operation module 126 to seta shooting mode, image processing control parameters, a layout, and etc.The information required for the setting is displayed on a LCD 127. Theimage data that was shot in such a way can be recorded into a memorycard MC that is inserted in a memory card slot 128. The image data mayalso be transmitted to an image output apparatus wirelessly via anantenna 125. The image data may alternatively be communicated via awire.

The operation of the digital still camera 10 is controlled by a controlcircuit 124. The control circuit 124 is configured as a microcomputerthat comprises a CPU and a memory therein. As shown is the upper half ofthe figure, the control circuit 124 comprises software-configuredfunctional blocks therein for such control.

An image data input module 11 receives image data via an image shootingmodule 12 or a MC input module 13. When the image shooting module 12 isused, the image data is generated by an image shooting operation in theoptical circuit 121. When the MC input module 13 is used, the image datais loaded from a memory card MC.

A control data setting module 14 sets control data to store the data inan image file along with the image data. The control data is used tocontrol details of image processing that is performed on the image datain the process of image output. The control data setting module 14analyzes the image to set the control data. The control data may reflectpreferences of each user in the process of setting. In other words, incase where a user has previously set adjustment data to the digitalcamera 10, indicating his preferences such as “higher sharpness, highercontrast” for example, the control data may reflect these preferences inthe process of setting. The use interface for the process of setting isprovided by an operation input module 15 and a display control module16. The display control module 16 provides the user with information byusing the LCD 17. The operation input module 15 inputs operations thatare performed with operation buttons 126.

An image file generation module 17 associates the data that wererespectively received from the image data input module 11 and thecontrol data setting module 14 into one file and stores the file,thereby generating an image file. The image file has a structure similarto that described above with respect to FIG. 1.

The image file thus generated is output by a transmission module 18 or aMC output module 19. The transmission module 18 controls the wirelesscommunication with the antenna 125. The use of the transmission module18 allows for the transmission of the image file to an image processingsystem 100 via a network INT. The MC output module 19 controls writingoperations into the memory card MC. The use of the MC output module 19allows for the passing of the image file to the image processing system100 or any other external device by using the memory card MC.

B. Generation of Image File

FIG. 3 is a flowchart of the generation processing of an image file,which is performed by the control circuit 124 of the digital camera 10.The processing starts when a user focuses on an object and presses ashutter button halfway down. When the processing starts, the controlcircuit 124 performs a high-speed analysis in step S10. The process isperformed to analyze an image that was obtained in CCD so as to adjuston-shooting characteristics such as exposure, white balance, and etc.

When the analysis is complete and the shutter button is pressed all theway down, the control circuit 124 then performs recording of an image instep S12. At this time, voltage signals obtained in the CCD aretemporally converted to RGB data as described previously.

The control circuit 124 then analyzes the image and sets control databased on the obtained RGB image data in step S14. As describedpreviously, the control data includes color space parameters and colorcorrection parameters in the present embodiment. The color spaceparameters are determined previous to the image analysis, according tothe color space that was used at the time of shooting. On the otherhand, the color correction parameters are set based on the imageanalysis, and include: contrast, brightness, color balance, whitebalance, chromaticness, sharpness, memory color, and etc. As an example,image data Pd is illustrated is FIG. 3. The image data Pd is configuredas a two-dimensional array of pixels (each shown as a square) that arearranged in x-direction and y-direction. The pixels may sometimesrequire two-dimensional analysis on their tone values depending on thedetails of the image analysis, e.g. in case where the sharpness is to beset. In such a case, the two-dimensional analysis is preferablyperformed from the viewpoint of the improvement in image quality.However, only simplified analysis in the x-direction or in they-direction is performed in the present invention from the viewpoint ofthe speeding up of processing speed. As for the color correctionparameters, not all of them are necessarily set based on the imageanalysis, but only some of them may be set so. Alternatively, the colorcorrection parameters may be a mixture of two types of parameters:parameters that are set based on the analysis of the image data; andparameters that are previously prepared irrelevant to the image data.

A method of setting color correction parameters are described in thefollowing by taking a setting of contrast as an example. The controlcircuit 124 scans the pixels of the image data Pd progressively toobtain a distribution of brilliance Y. Since the image data Pd is RGBtone values in the present embodiment, values corresponding to thebrilliance Y may be calculated based on these tone values. The contrastcan be modified by converting the brilliance of each pixel through aformula “y=aY+b”, wherein a and b represent real-valued coefficientsthat define a method of adjusting contrast. In the present embodiment,each of the coefficients a and b is set as one of the color correctionparameters in step S14. The conversion process is performed in the imageoutput apparatus with the use of the coefficients and the conversionformula.

The coefficients a and b can be set in various way, e.g. by a methodthat uses the distribution of brilliance Y. For example, thecoefficients a and b can be set by using a maximum value Ymax and aminimum value Ymin of the brilliance Y in the following formulas:a=255/(Y max−Y min);b=−a*Ymin or 255−a*Ymax.

In this manner, the distribution of brilliance can be extended to thefullest extent. Alternatively, each end of the actually obtaineddistribution of brilliance may be truncated by a certain range ofdistribution to define the maximum value Ymax and the minimum valueYmin. The coefficients a and b can be set in various ways and thecontrast can be controlled with the values of the coefficients. Thecontrol circuit 124 sets the values of the coefficients a and b based onan operational expression or a table that is previously prepared bytaking the shooting characteristics of the digital camera 10 intoconsideration.

Although the setting of the control data was described above withrespect to the adjustment of contrast, this process equally applies toother processing, so that the control data can be set in the form ofparameters or a table that is used for operations in the image outputapparatus.

The control circuit 124 may also reflect preferences of each user in theprocess of setting color correction parameters in step S14. As describedpreviously, in the present embodiment, preferences such as “highersharpness, higher contrast” can be preset as adjustment data in thedigital camera 10. The control circuit 124 can thus reflect theadjustment data in the process of setting the aforementioned parametervalues in step S14. For example, in case where the contrast is set to behigher, the control circuit 124 can reflect this adjustment data byfurther multiplying the above described coefficient a by a certainenhancing coefficient. It should be noted, however, that the effect onthe color correction parameters by the setting such as “higher” or“lower” is only a matter of design variation, so that such adjustmentdata can be set in an arbitrary manner.

The control circuit 124 generates an image file that includes theobtained control data in step S16 and stores the file in e.g. a mediumin step S18. The structure of the image file is similar to the onedescribed above with respect to FIG. 1.

Although the process of recording an image in the form of RGB data instep S12 and analyzing the data in step S14 was illustrated in thepresent embodiment, the image analysis is not necessarily based on theRGB data. For example, the control circuit 124 may record other types ofdata, e.g. the data that was obtained in the CCD (referred to as RAWdata herein after) or the data that was converted into YCbCr data, instep S12 and may perform the image analysis based on such data. Itshould be noted, however, in case where the color space of the imageanalysis is different from that of the image processing, it may bepreferable to predefine a method of setting control data so that both ofthe result of the analysis and the difference between the color spacescan be reflected in the process of setting control data.

C. Output of Image

FIG. 4 is a flowchart of the image processing, which is performed by thecomputer PC that is a constituent of the image output apparatus.Firstly, the computer PC inputs image data and control data in step S20.The computer PC analyzes the image data, which is received via a networkfrom the digital still camera 10 or is loaded from the memory card MC,and extracts the image data and the control data.

The computer PC then performs a variety of image processing discussedlater. Since the image data is defined in the YCbCr color space in thepresent embodiment, the computer PC converts the image data to the RGBcolor space, i.e. a color space that was used at the time of shooting,in step S21. The conversion process is performed with an inverse matrixof the matrix that was used for the conversion from the RGB space to theYCbCr space in the digital still camera 10. The image data is thusconverted to an on-shooting color space, i.e. either one of NTSC, sRGB,or extended sRGB. In case where the image data is converted to theextended sRGB color space, the resulting image data includes negativevalues as well as values beyond 256 at this point.

The computer PC then performs a gamma correction on the image data instep S22. The gamma value that is used in the gamma correction isincluded in the control data as the information that representscharacteristics of the digital still camera 10.

When the gamma correction completes, a process of conversion isperformed to convert the color space of the image data to wRGB colorspace, i.e. a color space that is defined in a wider color reproductionrange than the sRGB. This is because if the image data that was shot inthe NTSC color space or the extended sRGB color space is processed inthe sRGB color space that has a narrower color reproduction range, theremay be a possibility that the colors of the object can not be reproducedexactly. In this view, the image data that was shot in the sRGB spacemay possibly skip some steps as will be discussed later. However in thepresent embodiment, since the color space information that is includedin the control data does not distinguish between the sRGB space and theextended sRGB space, the image data that was taken in the sRGB spacealso goes through the conversion process to the wRGB space.

The conversion to the wRGB color space is performed by matrixoperations. As described previously, the computer PC deals with theimage data that is defined in the sRGB color space or in the extendedsRGB color space and the image data that is defined in the NTSC colorspace. Although a matrix can be defined to convert each color spacedirectly into the wRGB color space, each color space is convertedthrough the intermediary of a standard XYZ color space in the presentembodiment.

Firstly, the computer PC converts the RGB color space to the XYZ colorspace in step S23. The conversion process varies according to the typeof the color space that defines the image data. In other words, bypreparing two types of conversion matrixes beforehand: a conversionmatrix TM1 for the sRGB color space or the extended sRGB color space;and a conversion matrix TM2 for the NTSC color space, and by separatelyusing one of them in individual cases, the conversion process can beachieved in response to the color space that was used at the timeshooting. In this manner, the image data can always be converted intothe standard XYZ color space, no matter in which color space the imagedata was shot.

Next, the computer PC converts the XYZ color space into the wRGB colorspace in step S24. The conversion process is also a matrix operation.The conversion process can be achieved by a single matrix regardless ofthe color space that was used at the time of shooting. The matrix thatis used for the operation may be set arbitrarily according to thedefinition of the wRGB color space.

As described previously, the image data that was shot in the sRGB colorspace does not require the conversion into a wider color space.Accordingly, the steps S23 and S24 may be skipped for such image data.In case where the NTSC color space is used as the color space that iswider than the sRGB color space, the steps S23 and S24 may be skippedfor the image data that was shot in the NTSC color space. In this way,the processing in the steps S23 and S24 may be skipped as appropriateaccording to the relative relationship between the color space that wasused at the time of shooting and the color space that is to be used atthe end.

When the conversion of color spaces completes, the computer PC performsan inverted gamma correction in step S25. The gamma value that is usedin this process is determined based on color reproductioncharacteristics of the output apparatus. In case where the type of theoutput apparatus is already known at the time of shooting, the gammavalue may be included in the control data that is attached to the imagedata.

Next, the computer PC performs an automatic adjustment of image qualityin order to reflect on-shooting intentions in step S26. In the presentembodiment, the color correction parameters are included in the controldata, and the computer PC automatically adjusts the image quality basedon these parameters. The method of image quality adjustment based oneach parameter is well-known in the art and is not described in detailherein.

The correction of the image data thus completes and obtains the imagedata that reflects the color reproduction characteristics of the digitalstill camera 10 and the on-shooting intentions. The computer PC thenperforms some processing in preparatory for the execution of printing.Firstly, the computer PC performs a color conversion of the image datain step S27, which is a process for converting the RGB color system intoa CMYK color system, i.e. a color system that is used in printers. Theconversion process is achieved by referencing a conversion-used look-uptable (LUT) that relates the colors of each color system one another. Atable LUTw, which is for the conversion from the wRGB color space intothe CMYK color space, is typically used in the present embodiment. Itshould be noted, however, that the computer PC can also deal with theimage data that is defined in the sRGB color space. The computer PC thuscomprises a table LUTs for the conversion from the sRGB color space aswell as the table LUTw, and selects and uses one of them according to inwhich color space the image data is defined. For example, the table LUTscan be applied to a case where the color space conversion process ofsteps S23 and S24 were skipped for the image data that was shot in thesRGB color space, and the received image file is output without goingthrough any adjustment of image quality.

The computer PC then performs half-tone processing on the image datathat was converted to have CMYK tone values in step S28. The half-toneprocessing is used to represent the tone values of the image data withdensity of dots that are created by the printer, and can be achieved bya well-known method such as an error diffusion method, an organizeddithering method, and etc. In addition to the above-describedprocessing, the computer PC may also perform other processing as well,such as resolution conversion processing for adapting the resolution ofthe image data to the resolution of the printer, interlace datageneration processing for setting the data array and the sub-scanningfeed rate in a way to allow for the interlace recording in the printer,and etc. The computer PC then directs the printer PRT to perform theprinting based on the generated print data in step S30.

The system of the present embodiment described above provides variousadvantages as discussed below. First, by setting the control data, thesystem can control the details of the image processing that is performedin the computer PC. At this time, the output state of the image can beadjusted while the original image data is retained without modification.Secondly, since the image processing is performed in the computer PC,the digital camera 10 can be reduced with processing load. Thirdly,since the control data is set based on the image analysis in the digitalcamera 10, the setting of the control data can make the best use of thecharacteristics of the digital camera 10 and of the image.

D1. Modifications

FIG. 5 is a schematic that shows combinations of modifications in thepresent embodiment. The present invention can be implemented in variousmodifications by combining: a method that analyzes image data to setcontrol data; and a method that uses the control data to output animage. Three variations are shown for the control data setting methodand another three variations are shown for the image output method. Eachvariation of either method can be combined independently with any of thevariations of the other method, so that total of nine configurations canbe implemented within the range of the illustration.

The control data setting methods can be distinguished into threevariations according to the type of processing target or image data thatis used in the setting process and the timing to perform the settingprocess. For the sake of convenience, the present embodiment wasdescribed in terms of storing an image file after control data is set.It should be noted, however, the process of storing may be modified toany of three variations of the image output method as discussed below.

A first aspect of the control data setting method targets at on-shootingdata, and is performed after shooting and before storing image data. Theprocessing is equivalent to the processing described above as anembodiment (see FIG. 3). In this aspect, control data is set in adigital camera DSC by analyzing image data that was just shot. The imagedata is then stored as an image file along with the control data.

A second aspect of the control data setting method targets at aninitially stored image file and is performed after shooting. In thiscase, the digital camera DSC stores the on-shooting data as an imagefile without performing an analysis for the control data setting. Atthis time, the image file may be attached with some control data thatdoes not require any analysis, e.g. a color correction parameter. Thedigital still camera then reads out the image file at a timing such aswhen instructed by a user, performs the image analysis, and then setsthe control data. Alternatively, the processing may be performed underlower processing load conditions irrespective of instructions from theuser, e.g. when the digital still camera DSC is not used for shooting.The image file is then stored again, this time including the controldata that was obtained from the analysis. Alternatively, only thecontrol data may be stored newly or the control data as well as theimage data may be stored again altogether. The second aspect of themethod can advantageously reduce the on-shooting processing load.

In the second aspect, the initially stored image file may take variousformats: JPEG compression format, RAW data format, and etc. It isparticularly preferable to store the image file in a format that canexactly maintain the on-shooting information, e.g. RAW data format. Thisallows for improvement in precision of reading and analyzing theinitially stored file, thereby enhancing the image quality. As describedpreviously with respect to the above embodiment, the image quality canbe analyzed in various formats: RGB data, YCBCr data, RAW data, and etc.After the control data was set by the analysis, the image file ispreferably compressed with JPEG format and then stored again. Thisallows for control of capacity of the eventually obtained image file. Ascan be seen, the image file that will go through the image analysis isstored in a format such as RAW data, whereas the image data that hasgone through the image analysis is stored in another format that hascompressed amount of data. This allows for reduction in capacity of theimage file as well as improvement in the image quality.

A third aspect of the control data setting method sets control datairrespective of shooting. The processing can be performed in a placethat provides image data to the computer PC, e.g. in a server. Theserver SV inputs a separately prepared image file and analyzes the fileto set control data. The server SV then creates and stores an image filethat contains the control data therein. The process of storing can beimplemented in various aspects in connection with the output methods asdescribed below. For example, the image data and the control data may bestored together as one image file, or only the control data may bestored as a separate file. The analysis of the image data is notnecessarily performed in a generation device that generates image filessuch as the digital camera 10, but may also be carried out in aprocessing device that performs image processing such as the computerPC. Throughput for the image analysis may be compared between thegeneration device and the processing device to determine whether or notto perform the image analysis in the generation device. The generationdevice may perform the analysis if the generation device has a higherthroughput, and the processing device may perform the analysis if theprocessing device has a higher throughput. The throughput of theprocessing device may be prestored in the generation device incorrelation with the type of the processing device, or may be obtainedby the communication between the generation device and the processingdevice. In case where the generation device does not perform theanalysis, the generation device may generate the control data thatinstructs execution of the analysis in the processing device and attachthe data to the image file

A first aspect of the output method is to output an image file, which isequivalent to the aspect that is employed in the above embodiment (seeFIG. 3). In this aspect, image data and control data are combinedtogether to form an image file, which is then output to the computer PCvia media or communication. In this aspect, the image data and thecontrol data can be transferred together, which makes the file easier totreat with.

A second aspect of the output method is to output an image file andcontrol data separately as individual files. The files are created asindividual files in this aspect. It should be noted, however, the filesare associated one another. According to the aspect, the control datacan be advantageously shared by plural pieces of image data.

A third aspect of the output method is to output image data directly viacommunication. For example, control data that was set by e.g. thedigital camera DSC is transmitted to the computer PCPRT viacommunication without being stored as a file. The image data may also betransferred via communication as similar to the control data, or theimage data may be transferred via media separately.

D2. Other Modes of Modifications

Although the present invention has been illustrated in terms ofincluding some color space parameter in the control data and performingthe color conversion process (e.g. the steps S23 and S24 in FIG. 4)according to the color space parameter when outputting images, thepresent invention may also skip such color space parameter-relatedprocess as well.

Although the embodiment and the modification are illustrated in terms ofusing a digital camera as an image shooting apparatus, other apparatusessuch as a digital video camera or a scanner may also be used as well.Additionally, the present invention is not only applicable to staticimages but is also applicable to moving images as well. As for movingimages, the processing of the present invention can be applied to everyframe that constitutes a moving image, or can be applied at certaintimings such as at every scene transition.

Although various embodiments of the present invention are describedabove, it is clearly understood that the present invention is notrestricted to the above embodiments, but there may be variousconfigurations without departing from the spirit of the presentinvention. The processing of control described above may be implementednot only in a software manner but also in a hardware manner as well.

INDUSTRIAL APPLICABILITY

The present invention can be applied to techniques of controlling imageprocessing that are performed in image output apparatuses and ofimplementing desirable image outputs.

1. An image output control apparatus that controls output of image datacomprising: an input module that inputs said image data; an analysismodule that performs an image analysis of said image data; an analysiscontrol module that controls operation of said analysis module based oncomparison of throughputs between said image output control apparatusand an image output apparatus with respect to said image analysis, saidimage output apparatus performing image quality adjustment of said imagedata; a color correction parameter determination module that determinesa color correction parameter that is used for said image qualityadjustment of said image data according to analysis result of said imagedata, said color correction parameter including at least one ofparameters relating to contrast, lightness, color balance, whitebalance, saturation, sharpness, and memory color; and an output modulethat outputs said color correction parameter in correlation with saidimage data.
 2. The image output control apparatus according to claim 1,further comprising: an image shooting module that shoots images; whereinsaid image data is output data from said image shooting module.
 3. Animage shooting apparatus comprising: an image output control apparatusaccording to claim 2, and an image file generation module that generatesan image file by relating said color correction parameter and said imagedata to one another.
 4. The image output control apparatus according toclaim 1, further comprising: a memory module that stores adjustment databeforehand, said adjustment data being used to adjust setting of saidcolor correction parameter; wherein said analysis module reflects saidadjustment data to set said color correction parameter.
 5. The imageoutput control apparatus according to claim 1, wherein said analysiscontrol module brings said analysis module into operation in a casewhere said image output control apparatus has a higher throughput. 6.The image output control apparatus according to claim 1, wherein saidanalysis control module halts operation of said analysis module andcauses said image output apparatus to perform said image analysis, in acase where said image output control apparatus has a lower throughput.7. The image output control apparatus according to claim 1, wherein saidoutput module outputs an image file that comprises said image data andsaid color correction parameter integrated together.
 8. The image outputcontrol apparatus according to claim 1, wherein said output moduleoutputs said color correction parameter as a separate file that isassociated with said image data.
 9. The image output control apparatusaccording to claim 1, wherein said output module outputs said colorcorrection parameter to said image output apparatus via communication.10. A color correction parameter setting method that controls output ofimage data, comprising: a process of inputting said image data; aprocess of performing image analysis of said image data; a process ofcontrolling the performing of the image analysis of said image databased on comparison of throughputs between an image output controlapparatus and an image output apparatus with respect to said imageanalysis, said image output apparatus performing image qualityadjustment of said image data; a process of determining a colorcorrection parameter that determines said color correction parameterthat is used for said image quality adjustment of said image dataaccording to analysis result of said image data, said color correctionparameter including at least one of parameters relating to contrast,lightness, color balance, white balance, saturation, sharpness, andmemory color; and a process of outputting said color correctionparameter in correlation with said image data.
 11. A computer-readablestorage medium that is encoded with a computer program to control outputof image data, said computer program causing a computer to implement: afunction of inputting said image data; a function of performing imageanalysis of said image data; a function of controlling the performing ofthe image analysis of said image data based on comparison of throughputsbetween an image output control apparatus and an image output apparatuswith respect to said image analysis, said image output apparatusperforming image quality adjustment of said image data; a function ofdetermining a color correction parameter that determines said colorcorrection parameter that is used for said image quality adjustment ofsaid image data according to analysis result of said image data, saidcolor correction parameter including at least one of parameters relatingto contrast, lightness, color balance white balance, saturation,sharpness, and memory color; and a function of outputting said colorcorrection parameter in correlation with said image data.